//实体箭头
.triArrow(@direction, @size, @color) {
    width: 0;
    height: 0;
    overflow: hidden;
    font-size: 0;
    line-height: 0;
    cursor: pointer;
    border-width: @size;
}

.triArrow(@direction, @size, @color) when (@direction = top) {
    border-color: transparent transparent @color transparent;
    border-style: dashed dashed solid dashed;
    border-top: none;
}
.triArrow(@direction, @size, @color) when (@direction = bottom) {
    border-color: @color transparent transparent transparent;
    border-style: solid dashed dashed dashed;
    border-bottom: none;
}
.triArrow(@direction, @size, @color) when (@direction = right) {
    border-color: transparent transparent transparent @color;
    border-style: dashed dashed dashed solid;
    border-right: none;
}

.triArrow(@direction, @size, @color) when (@direction = left) {
    border-color: transparent @color transparent transparent;
    border-style: dashed solid dashed dashed;
    border-left: none;
}
